Zinc in Soil
Zinc is a natural component of the soil. There are soils with low levels of zinc and those with high levels. Zinc occurs in the form of ores in the Earth's crust with an average content of 70 mg/kg, which corresponds to a share of 0.007% or 198,000,000 Mt in the Earth's crust. Weathering and erosion of rock, soil, and sediments by wind and water naturally circulate small amounts of zinc, making it available for plants, animals, and humans in drinking water and food - the trace nutrient zinc is essential for physical development and responsible for a range of body functions from enzyme and blood formation to hair growth. The human use of zinc and resulting zinc discharges play a far lesser role compared to natural ones. The highest zinc entries from human activity are recorded in agriculture through the use of fertilizers, manure, and slurry. Zinc in wastewater from households through the use of personal care products, pharmaceuticals, ointments also ultimately affects our soils due to the use of sewage sludge. Discharges from building products today have no significant environmental impact. The cause of zinc discharges from roof surfaces and zinc corrosion-protected constructions, identified as 'acid rain' in the 1980s and 1990s, is no longer present due to a variety of environmental measures from desulfurization plants in coal-fired power stations to car catalytic converters. As a result, the zinc discharge from zinc surfaces has been reduced by up to 90% since 1970. Runoff from roofing usually contains less zinc than is allowed in drinking water.
Rainwater is often collected from sealed surfaces on buildings in decentralized facilities (swales, trenches, etc.) and fed to the soil and groundwater - a practice that benefits the urban microclimate, groundwater regeneration, and relieves sewage treatment plants. The vegetated topsoil (recommended permeability coefficient kf 10-5 [1]) of a soakaway pit performs a cleaning function. For zinc discharges, this means the permanent binding of zinc ions in the upper 3-5 cm [2] [3] of the soil zone. These zinc ions only very limitedly reach the groundwater.
Simply check whether the environmental quality targets for zinc are being met in your project. Perform the RainwaterCheck-ZINC here:www.zn-rate.com
The RainwaterCheck-ZINC calculates the zinc emissions at your site and compares the environmental impact (immissions) with the official quality targets and precautionary/minor threshold values (GFS) for soils and groundwater.
[2] Bertling, S., Odnevall Wallinder, I., Leygraf, C., and Berggren, D., “Environmental Effects of Zinc Runoff from Roofing Materials – A New Multidisciplinary Approach”, Outdoor and Indoor Atmospheric Corrosion, ASTM STP 1421, H. E. Townsend, Ed., American Society for Testing and Materials, West Conshohocken, PA, 2002
[3] gfw Wasser/Abwasser - Räumliche Verteilung der Schwermetallgehalte in den Oberböden von 35 Versickerungsmulden für Verkehrsflächenabflüsse Nils Horstmeyer, Maximilian Huber,Jörg E. Drewes, Brigitte Helmreich
Literature reference
“Environmental Effects of Zinc Runoff from Roofing Materials – A New Multidisciplinary Approach”, Bertling, S., Odnevall Wallinder, I., Leygraf, C., and Berggren, D.
Neue Erkenntnisse zur Deckschichtbildung von Zink an der Atmosphäre, Fakultät für Georessourcen und Materialtechnik an der RWTH Aachen, Martin Babutzka, 2020